Testing apparatus for determining the mechanical behavior of metals under test



Feb. 17, 1948. J MANJOINE 2,436,317

TESTING APPARATUS FOR DETERMING THE MECHANICAL BEHAVIOR OF METALS UNDERTEST Filed May 23, 1944 3 Sheets$het 1 INVENTOR 57a Q 45 50aM/c/me/IMa/yo/ne.

[(2%) RNEY.

Feb. 17, 1948.

3 Sheets-Sheet I5 Def/ea/v'on INVENTOR fli/chae/J/ian/a/ne.

I AT NEY MANJOINE BEHAVIOR OF METALS UNDER TEST TESTING APPARATUS FORDETERMING THE MECHANICAL S E S S E N H W Patented Feb. 17, 1948 TESTINGAPPARATUS FOR, Dfi'liiiiitfi THE MECHANICAL BEHAVIOR OF UNDER TESTMichael J. Manjoine Pittsbui-gh, Pa'.,=assigno r to WestinghouseElectrieCorporation, East-Pitts- =burgh, Pa -a corporation of PennsylvaniaApplication Mai "23, 1944, Ser'ial-No. 536;947

(o1. as -15.6)

'10 Claims.

My lnvention relates to metal testing machin'es and, more particularly,to machines of this char-- sister for determinin'g the mechanicalbehavior of am'etal or metal alloy at a'glven stress and at a given hightemperature, including the "creep or pl'astic extensionand-'fractureas aresult of the stress and thehightmperature.

The increas'eduse of'hrietal alloys under high temperatures during thelast few years 'l'ias rendered itdesii'able to understand moredefinitely the-efiects of heat treatments onsuahmeta'r'altoys, "and howthey will react under long service in high temperatures. one 'r'nethodof securing this information 'is to make iise of data from creep-timecurves carr1ed toruptu're, the curves being prepared from data obtainedby holding the te'st'specimen ate. constant load ln-a constanttemperature and noting the extension of the specimen until it becomesruptured. The =loabls for these tests are ehosento eause rupture ofth'especimensafterdifierentp riods which may vary from a few hours to'several' thousand hoiirs, and it is 'desirable to have -'a's near as"possibleacom tinu'ous record of elongation of the specimendue =to'creepwith time. Ifs hort 'tests are used, "lasting'from a few hours toseveral hundred hours, it is tliflicult' to obtain suifi'cient [readingst'o'dralw a complete curve to rupture. If long tests ex tending as-lon'gas -1,-000-or}more'hours are used, it i's 'dificult and. expensivetogive such tests-the 'iieces'sary attentionto insure'a sufiicientnumber of readings over the length of time necessary for the te'st.

'Therefore, one object or m invention istoprotide a testing machinewhich will, after being loaded with atest specimen "ands'tarted make acomplete test ofthe spe'oimeh, automatically p'rodime a creep tinietmrupture curvefor the specimen-and then stop' the operation of themachine. {A further olojec'tofsth'e invention 'is to 'prov'iiie at'stapparatus having no 'extens mete'r on the K's'till'furtliel object istoprovlde a testil'fgap- 'p'aratus which shall be simple and inexpensivein construction and operation-and which will '00- cupy a very'smallfloor space -It is a-Isoan object to provide atesting -appa+ ratus whichwill operate apen over a curve'sneet during "a test and which willcontinue to register on a separate'device the amountof theoreep of thetest specimen until it ruptures, "even- "though the recordingrpenmayleave tli'e curve 'sheet upon which itis operating, so that suchregistered-see:

2 0rd may be used for c 'nfpletlng the creep-time curve.

Although my improvedx'riael'line is designed na'rti'cularly for"producing oreep-time-to-ruptu're t curvesglt is also usetm for-(d)sorting metal alloys, (b) checking lieattreatmentsofmetal altoys, ('0)making qualitytestsfor'checking several meltsof a' metal'alloy, td)making rupture tests'on a p'artitEuIar metal alloy, and (e) runningconstant'strain 'ratetests,short time tensile tests, or relaxationtests.

For a better understanding of "the invention, reference may behadtoth'eaceom anym drawings'in' which: I

Figure 1 is a new in fr'o'nt elevation of a testing apparatusemb'odyi'rigmy invention;

Fig. 2 is a viewin 'siile elevation of the testing apparatusilllist tedih'Fig; 1

Fig. -3 is' an enlarged view, in front elevation of the force measuringbar included "inthe apparatus;

Fig. 4 is an enlarged topfijlah or the testme apparatus illli'strattl ihFi'g's. l and 2;

Fig. 5 is an enlarged view l front elevation of the curve s'h't boafd'elhd marking device mounted on the iipioer front bortion of the testingmachine 'illustratefl i'n Figs; 1 and 2;

Fig. 6 is a sectional Viewthrough acente'r of the *loading jack mountedin the upper part of the testingapparatiisshown in Figs. 1 "and 2;

Fig. "7 is -a diagrammatic representation of the electrical controlsystem for the testing 'apparatusi'and Fig. 8 fefie'seiits a typical tworange curve resulting from 'riiy prove measuring 'bar.

Referring more streamer-1y to the drawings, 31 have illustrated atesting inahhine having an upright rectangula-i like --fra'me comprisinga base plate loparpaivor c ann-el irons l l and I2 Vertically disposedon the base plate and secure- 1y sealed thereto 'ziifidza top plate l3securely Welded to the upper 'n'eis oftlfe eh'annel irons. A pluralityof 'gus'eet's are "welded "to "the corners of the frame toiveitadditional strength. The partsor the-frame'should be male of very heavymaterial withr'efer en'ce to -th'e-r'ange of dimen- Siohs or the testsp-e'cimefis tobe tested so that which the lower end of the testspecimen may be screwed and its lower end is screw threaded so that itmay screw into the upper end of a turnbuckle |8, the lower end of whichis screwed on a shaft H] which is firmly screwed into the bottom plateI0. I The grip IS, the turnbuckle l8 and the shaft I9 thus provide asuitable means for anchoring the lower end of the specimen to thebed-plate of the testing machine.

The loading grip II is provided with a screwthreaded recess in its lowerend into which the upper end of the test specimen 5 may be screwedsecurely so that its slender c ntral test portion may be placed underany desired strain. The upperend of the loading grip extends upwardlythrough a cross bar and a nut 2| is screwed on it to hold it firmly inposition. The cross bar is secured to the lower ends of a pair ofvertical rods 22 and 23 which are vertically and slidably disposed inthe top plate I3 of the machine. A force measuring bar 25 is mounted onthe upper ends of the rods 22 and 23 by means of suitable nuts 26 and21, so that the cross bar 20. the rods 22 and 23 and the measuring bar25 p ovide an auxiliary frame or loading means for applying a stretchingload to the test specimen.

A loading jack 29 is mounted on the top plate l3 in position to engage asocket in the underside of the measuring bar 25 and thereby provide ameans whereby an upward force may be applied to the measuring bar toraise the rods 22 and 23, the cross bar 20 and the grip i1 and thusapply a testing load to the specimen l5.

The loading jack 29 comprises a cast frame or housing 3|, ascrew-threaded jack shaft 32, a worm wheel 33, and a worm 34. Thehousing 3| is provided with a depending portion 35 and a centrallylocated flange 36 by means of which it may be seated and supported in acentrally located hole in the top plate l3. The screwthreaded jack shaft32 is disposed in a vertical hole in the central portion of thehousingand is provided with a slot 31 disposed to be engaged by a key whichpermits it to slide up and down in the housing but prevents it fromrotating. The worm wheel is mounted in horizontal position in the centerof the housing and is provided with an inwardly facing screw threadwhich meshes with the screw thread on the jack shaft so that rotation ofthe worm wheel in one direction will raise the jack shaft and in anotherdirection will lower the jack shaft.

The worm 34 for operating the jack shaft is mounted on a suitable shaft40 arranged to be driven by a motive means such as a small alternatingcurrent electric motor 4!. The'motor is mounted in a suitableposition-between the channel sides H and I2 and is operatively connectedto the worm shaft 40 through a main gear mechanism comprising a pulley43, a belt 44, a pulley 45. a shaft 46, a suitable gear reducing means41, a pinion 48 and a gear wheel 49.

In order that the force applied by the jack to the test specimen may bemeasured, the measur ing bar is constructed out of a block of alloysteel by making a saw cut or slot 50 in its lower central portion toconvert the lower section of the bar against which the jack rests into aresilient segment or spring bar 5|. Thespring bar will bend upwardly inaccordance with the upward force exerted upon it "by the jack; When thetest specimen elongates during test, it reduces the downward pull of therods 22 and 23 on the ends of the measuring bar and thus permits theends of the measuring bar-to moveupwardly, thereby permitting theresilient segment 5| to return toward its normally straight conditionand thus decreasing the load on the specimen.

A pressure indicating instrument 52 is mounted on the measuring bar by abracket 53 in such position that its plunger 54 will be operated by thebending action of the resilient bar. The instrument is provided with azero indicating pointer 55, a rotatable dial 56, an indicating orcontrol hand 51, and an adjustable hand 58. The plunger is operativelyconnected to the control hand 55 and extends downwardly through a holein the measuring bar until it is seated on the spring bar 5| so thatwhen the central portion of the spring bar is bent upwardly by the jackit will operate the plunger upwardly to move the control hand 51 to theright. The zero pointer 55 is mounted on the rear of the instrument andbent over its casing to point to the position in which the control hand51 will be when there is no load on the test specimen. This will be thezero point.

In order that the measuring instrument may be used as a switching devicefor controlling the motor 4| to increase the jack pressure whenever thetest specimen elongates sufiiciently to decrease the load on it, therotatable dial 56 is provided with a pressure scale reading up to 4,000pounds in anticlockwise direction, a contact segment 59 is glued to thedial in position to project into the path of the control hand 51 at itsleft-hand side and both the contact segment and the control hand are soconnected in the control system illustrated in Fig. 7 that they can beused to control the motor 4 I. For instance, if the dial is at zero andthen is turned clockwise until it moves the control hand to a pointindicating a load of 2,000 pounds, the motor will start and run the jackup until the load equals 2,000 pounds, when the control hand will movebeyond the contact segment and thus stop the motor.

The satisfactory operation of the machine depends on how constant theload presented by the deflection of the spring bar 5| can be maintained.When the specimen elongates, the load drops a small amount, and the loadmeasuring bar must be sensitive enough to respond to a change of load ofabout 0.1% and also must be rigid enough to withstand the shock when thespecimen breaks and suddenly releases the entire load, In addition, itmust be sensitive over a wide range of loads. To meet theserequirements, I make a second saw cut or slot 50a in the alloy steel barto produce a second spring bar 5|a above the spring bar 5| and constructa small boss 5|b on its lower central base such a distance from thefirst bar 5| the first spring bar in response to a 4,000 poundhpressure, thus giving a total range of 20,000

pounds for both bars. Normally the spring bar is so made and theinstrument is so selected that the initial bending of the bar up to thepoint where it engages the boss on the second bar will rotate thecontrol once around the dial and the dial may be marked to read directlyon the pressure measured during that rotation. However, when the.

first spring bar contacts the second spring bar and both becomeeffective, the control hand will be on its second trip around the dialand will in dicate a much heavier load by each markon the rdiasiflonsequentlrrthemeadin :ofzthe-diahdurms the second tripof the handaroundtittwllhhavato the made with tthat mind. 2A. trpieal deadidefletioncourreitorrthei-twdrangesaofttheameas- 6 258:1!tfiutingsactestnisrthessame as theeextension ifl'fithfi' test: pecimen.a'liheaccuracwotthis'imeafiurement of elongation depends on thelfioliowing 'iconditions. fli iinoec-the dead: and tempera'turei'are:uring bards imdicatedinrFigaa, therange 'tomthe 5 ,rheid'zconstant.the-thermalsand elastic :deflections first. har:- 5I:.-a1one;heing;indicated. Joy). theeletter'za and the-ransetorzbothbarszacting o e herbein indicated hyitheiletterob. he.' 11S i0 tih two spring bars does notaffect theooperationnofxthe 20f itheeentiressystemKare, fixed..Therefore, the .zrelativermotionaof the heads ofthe machine' ithe smovementeof 171185 jack) is caused bysthe plastic flowrofxthepartsof"the-zsystem-:which consist pripen-nr the counterimeter butdoes-i-ohange:thehlfl:marilyoftheiextensiompieces@andithe-specimen.

readingtandsaction of, -.the::contro1-. hand-on th measurin:1nstmment,,-thuscausing-the motonito start more oftenin "the -..1,ow:range 1 than imthe vhigh rangesm that the instrument will :be veryThF-CI'OSSYSECfiiOH-fil areajof: the: extension pieces in thehohzonemfithe-funnace is:-over= four timesrthat ofiltheegaugelength.-The'. creep ratein the. ex- 11611519113 rpiecesw-will: :be Jess-thans=01%- of thatsin sensi v -sternum. loads; andsthe motor will-keepi the eauge length. Theheadset-thespecimenare the.-.constant40nd,ace-hrate'lyv his the Jowrangemf Pressure.

The use;of.;the two-,barapermits the-accurate measurement of-small loads"as-Welds largesloads.

flhe m asuring-a bar need not :be 1 limited to two gmpringbarStthatiatwo ran es, but-accuraenww de reas as the 1 number of.:bars :or an ncreases. lAlthou heaasensit ve ia a u flsfld to ndiatetheload, nO h0Qk= is placed one the .ialsorzmadealarge .to reduce thecreep. Inasmuch as .-the-:extension if the specimen *correspondsttoinstrumenthecauseatheespringibardeflectsaaway of the iioint-cqperationof the .jack-operating from the;\,piuneer When the; load decreases.

.'I,hesadju,stab1ehand 58 1 is 1,3180 provided -:With

a contact on its outer end in the path .or the hand t and 1 is imvotallymounted .on the .front never mechanism nand a, clock mechanism 113 i for=09- .erati-ngsa recording member such as a: pen tozautomaticaliytproduce acontinuous creep-timeto-rupture curve for thespecimenundertest upon of the installment. A-akneb;58a is attachedtothex39 1a icnrve-sheetastipported:onsa board 15.

hand 58;]oy whiohit mayrtbeimoved to any desired positiQn. The hand '58issQ-cQnnected-in the control system lofeE ga I;tr-rat:contacifn-ofthe-handsj and Sit-twill cause: reversal ofthe t-jack motorr .TAt

, Theeurvezshet board 1 51s mounted: in a vertiicahpositiont antherfront-edge vof-rthe top, plate t3 by; means otsuitable: brackets l5 andl I 1 inisuch sipositionethata-icnrvessheetmay be:easilymountedthetstart of ,aztest; the, reversinghandafifl is turnedlon-ttheiiacetthereof by flf 1- D -9 clockwisetwellraway fromtheicontroi hand. After the d al. isadjusted, the reversing hand is;turned counterclockwise-to a position whieh; representsia load :oftapproximateiy 17% greater thamthevload at-which the-hams set.

electric furnace -60: is pr vided; for. heat ng the test shqfiimentoany. desired, testtemperature. The furnace-r605is'constructed with.-a;-cy1indrica1 outer housing s6 I and an; inner: housing :62.

provided :with heating windings hit-disposed in Suitable insulating.material adjacent-to the; inner housin for h at ng the test specimen.The windas as; is usual-1 for-electric: furnaces-of the show-n,are-zdisnosed to barman-inductive.

,Athermb fluplexontrol device fi l-is disposedin the midsectioniofthefurnace and is-interconnected with :a control device or regulatormounted-onthesohannel iron H join-maintaining the: temperatureinwtherfurnace constantlyt at: any

se1ected-..-ternheature.- The-electrical energy tier :55

.trqn edge 9i Jthetchannel s iron J2 v3 eatpairt if brackets and H..As-;shown,hy.the dotted; lines 12 in Fig; .,,the,f11mace;may be dr ppeddowmon the ro 55 an swungoutto the one side ofth test ngmadhine tofacilitatei-themakin .Qf any r pai s .o adjustments- Whenthe specimenisunder test in: the furnace it elongates as itcreeps withtime andthispermit's the elastio segrnentiof themeasuringtbar to. non..- tractaslight amount. As noted before, this small ontractiohis .llsed tostartthenmotor toiraise .the lack untilrngmad on the testrspecimenisrestoredI lhe senate rod-.6 B. :isn'otatahly :mountedzon Snotchtare.

llhe. pen ithisrmounted. in frontof the board and in-positiontoroperabiysbear against the curve sheet gtheregn by pen carriage.comprising :9, :eross :bar-7l8; azscrewathreaded drive bar T-S'and-a.pairriof nend members :and 8|. The and members M80 and 8] sare mounted-.by' means of KSCPEW threadedeonnections ona-pair of vertical screw(threaded ":sha'ftss8 2 (and, -83 so that opera- The penis supported sonthe carriage by a Mesh-apedachp (I-4a, which is seated by a screwthreadedrseeti'on on thetdrive shaft 19. Alsprin Ribs-is :attaehedsto-the-elipsinsuch position that itssend nohtionsarea-slid-ablydisposed in a groove -IBwintheacarriagahar 1.8 ;to provideahmeansfor slidabty sand irictionahy positioning the pen moun,onritscdrtvnsshaft. .The :penclip 1 darn-ray he, ditteed :irom. :thedriv shaft and :may heme; planed-I on [it in 5 starting, :position,adjacent to the, olookmechanisrm at anyztime.

The jaok r mechanism is zconnected to operate the screw threaded shaft:82 tbvyiantauxiliary {gear mechanism scomprising a 7 gear wheel 92, 1ashaft 9:3, -a gear'wheelsiid, -a fpinion 95,21. stub shaft 416, :andheveledggear ialrandtfi .Theshait 931 .11 tatably -.m0unte .d .inthebracket 11 and-a :hracket SB-on .the,.p1at.e l3. Isl-The shaftisrotatahiy sup- .portedtinthebracketdfl. The gear wheel (92 vismounted-onions end of .theshaft I95 in position to mesh with theegearwheel 49, on theijack-worm thusheqpinesthesload .constant. fill-1erisesof "the $5 shaft anditheisear, wheel at is .mounted on=the otherend of the shaftin position to mesh with the pinion 95 mounted on theinner end or the stub shaft 96.

The beveled gear 91 is disposed on the outer end of the shaft 96 inposition to mesh with the beveled gear 98 on the screw threaded shaft 82so that rotation of the gear wheel 49 in raising the jack will causerotation of the shaft 82 and thereby move the pen carriage in a verticaldirection over the curve sheet. The gear wheels 92, 94 and 95 and thebeveled gears 91 and 98 are made of such size that, in conjunction withthe worm 34 and the worm wheel 33 of the jack, they mechanically magnifythe rise of the jack and thus cause the pen to make a much magnifiedrecord of the elongation of the test specimen. For example, the gearsmay be selected for such magnification so that the pen carriage willmove one inch for each one one-hundredth inch of elongation per inchor astrain scale of 1% per inch. Further, the gears 94 and 95 may be readilychanged to give other magnifications.

When it it is desired to return the carriage to its lower position for anew test, the set screw holding the pinion 95 is loosened slightly, thepinion is then moved out of contactwith the gear wheel 94 and the chain88 is pulled in reverse directlon until the carriage is returned to itslower starting position.

The clock 13 for moving the pen in horizontal direction in accordancewith time is electrically driven and is mounted on the carriage member80 in position to rotate the driving shaft 19 through a worm I driven bythe clock mechanism and a worm wheel IDI disposed on one end of thedrive shaft, The clock is electrically connected in the electricalcontrol circuit of Fig. 7 by a manual switch 13a in such manner that itwill start when the control system is started for a creep-time test andwill continue in operation until the test is stopped either by thebreaking of the test specimen or by disconnecting the control systemfrom its source of energy. The manual switch 73a is provided fordisconnecting the clock while mak-.

ing preliminary tests before starting a creeptime-rupture test. Theclock may be adjusted to advance the pen at any desired rate. Forexample, it may be set to cause the pen to travel at a rate of one inchin an hour or at a rate of one inch in twenty hours.

When a specimen is to be tested, it is desirable to take the loadingcurve while applying the load for the creep-time-rupture test. Forexample, if a creep-time test is to be made at a constant load of 8,000pounds, it is desirable to make readings on the rise of the jack at,say, 2,000; 4,000 and 6,000 pounds or some other increments of load. Itwill not be desirable to start the pen on the curve sheet during theloading. Therefore, I have mounted a counting mete r H2 on the upperpart of the curve board for indicating the rise of the ack The meter isoperated by a beveled gear H3 fixed on the outer end of the shaft 93 anda beveled gear H4 on the meter so'that it will respond to rotation ofthe shaft '93 and thus give amagnified record of the extensionof thejack. The gearing and the numerals on the meter are so selected that themeter reading will indicate the same distance as that which would hetraveled by the pen were it connected for operation. For instance, fortypoints on the meter may indicate an inch on the curve sheet. Themetermakes a continuous record and the tester secures records from it bynoting the reading at the start and then at the end of the increment ofload; the

difl'erence giving the magnified distance for the rise of the jack. 1

The meter will also serve another purpose in that it will continue theelongation record even if the recording pen move off the curve sheet ina creep-time-rupture test before the specimen ruptures and from thisrecord the curve drawn on the curve sheet may be extended to give acomplete curve for the test.

An automatic means is provided for disconnecting the control system andthe clock when the test specimen breaks, by passing a control currentthrough the test specimen. Some test specimens will rupture withoutmaking a clean electrical break because small splinters or fragments atthe point of rupture will maintain electrical contact sufiiciently tomaintain th control circuit, In order to avoid difliculties of thisnature I have provided a spring H5 for raising the pulling grip l1upwardly sufficiently to separate the fractured parts of the rupturedtest specimen. The spring is fiat and is formed with an upwardly bentcentral portion and is disposed on top of'the cross bar 20 andunderneath the nut 2|. Thecontrol circuit is connected by a conductorHi; to a metal washer H! which rests on a strip of insulation materialH8 placed on top of the cross bar.

An insulating tube I I9 is disposed on the upper grip to insulate itfrom the cross bar. When the nut 21 is tightened to hold the testspecimen in test position, it forces the spring-H5 downwardly intoelectrical engagement with the washer. When the test specimen breaks,the spring bends upwardly and lifts the upper grip and the nut 21 I thusbreaking the connection with the washer and thereby opening the controlcircuit through the test specimen regardless of the condition of theruptured ends of the specimen. This action plus the forcible separationof the ruptured parts of the specimen ensures disconnection of theauxiliary control circuit to stop the clock and open the main controlcircuit when the test is completed to rupture.

In the control system illustrated in Fig, 7, a pair of supply conductorsL+ and L- are provided for operating the motor and the various controlrelays associated therewith. The con ductor L+ is disposed to beconnected to the relays and the motor to constitute one side of thecontrol circuit. The conductor L- as well as the motor and the variousrelays are indicated, for the sake of simplicity, as being grounded tothe frame of the test specimen to provide the return side of thecircuit. A main line switch MS is used for connecting the supplyconductors to a suitable source of electrical energy and a push button Bis disposed in the auxiliary control circuit through the test specimenfor starting the system in operation when a test is to be made. When thebutton B is closed, it energizes a holding relay H to maintain theauxiliar circuit through the test specimen until the speciment rupturesand stops the test.

The motor is provided with a rotor MR, a main field winding MF disposedto be connected to the supply conductors by a starting relay S, and areversing field winding RF disposed to be controlled by a reversingrelay R. An up direction relay U and a down direction relay D areprovided for controlling the starting and reversing relays. Inasmuch asthe contacts on the hands of the switching instrument 52 are necessarilyso small as to be able to carry only a small current, they are connectedto control an up direction amplifying: tube UT and a down:

direction amplifying etuber' DT for'causing energization of theupdirection relay :U when the jack is to be raised andforcausingenergization of thHdOWIU directionrelay -llwhen-the jack is tobelowered; In order'to stop the motor temporarily during a test, anup-manual switch KU and .a down manual lswitch' KD areincluded in thecontrol circuits.

Assumedoperation It will ibe assumed ithatr. atest specimen. of 0.505inchediameterxwill be'=:given:. la" creep-time to rupture-wisestatiazconstanttemperature and:v at azconstant-1oad. 'of;: say; 8,000pounds Whileapplyingthe full-=load, it isxadvisable .to'make series ofloading-readings; say,-1at.:.2;000 pounds,

4,000 pounds-and .6, 0.00 poundsfto detect any plastic flow whichmay:.'occuriduring.;the applicationoftheload;

'I'oaprepare the machinea'forsloading .it will be assumed that; the:clock switch: 13a is opened to' prevent-:operation.:of the sclockmechanism until.

the creepi-timetestnat; constant load is started; that the .penncarriageis im its \lowermost position: and fadj acent" to :the :clock mechanismthat the piniomSB :has 'beenimovedzout oia engagement with the.geanwheelgfldti that :a::cur=ve :sheet has been: placed 101).:the.;curve :board'; 1that1the read ing of the imeter. Iiithasbeeninoted onithe curve sheet.;-:;that the dial has:;:its zero=point disposed; ate. the i zeros pointer: 55 ziwith' ithe I control:

hand: against .thescontact :59 ionii the dial; that the reversirig 'hand358a:is;moved clockwise wellaway from: the :controb hand 1 and that thefurnace 60 is-initslower-positionzi It will: be :assumedznowthatvthetest=specimen isvinsertedinzthe machineibyscrewing its lower.

end into'thesuppen. endrofzzthezanchor grip i6 and byscrewingftheuppengriptfl to the upper end ..of=ithe spe'cimenuandi then putting onthenut '2 i; Theiturnbuckle i nnow-tightened :totake upany. lost.motioniin theiassembly and hold the specimen. firmlyi instestz'position:- Th'exfurnace 60 Iisnow raisedzto Plt's .normahp'ositionaround the test"specimen:andtconnected to its-source ofelectric'ali.energyrlnot shown). ands-the ziurnace controller-:is::-sett'.toho'ld tthe-r-furnace at. the desired constantitemperatura-au After .'the furnace: heats upzitheyspecimen, @the nutll.:is tight.- ened 1:170 :applyz-zat-small .initiakloada The. dial. 56

on the. measuring; instrument: 1 is now turned clockwise until its:2,000pound: pointaisatthezero pointerr55n. Thissaclockwise z'rotationof; the. diaL causes the2:projectin conte'mtsfiii-v to r carry. thecontrol. hand 51* along withlitl'to its". 2,000 pound.

ingjiiom: conductor 11+; througheonductor .I 22,-

tube -.UT,-. conductor 123; contacts 5912;111:1 51 ofv the instrument52. and ground rtoconductor L-. The energized tube- UT causes:-sufficient: current to flow to-the: upsdirection 'relaytu to energize;it.

anaemia;

thusiopenlng'aits contactsaUziand closingaits con t'actsrUl; Theclosingotthe icontacts Ui enter-- gizes :the starting relay '8; bythe 'circuit-L-+, l2 i H1, I24 U1, .3; I25;- Dz andaground toL-; Theenergized'nrelay's closesitskcontaots S i and S2 thereby' energizing.the main field winding 'M'F:

Inasmuch as the relay R is not. energised at this timefiits contactsRT-and Rfi remain closed so that thereversingrfield windingRF is:energized-for op; crating the'ijack in theupz'dihecti'on: The energization' 'ofv-ther-fi'eld. windings :MF-and iRF starts the motor tooperate thecjackfor the purpose ht" loadingethe specimen up to :2}000pounds.

The operation of the motor. causes eorresponm; irigt'operationz of thepulley; belt' l i-g pulley '45,: shaft '06; reducing. gears 4l 'pinion-twflgear- 49," wormed and Warm wheel33 toimovethe iackshatt iiiupwardly. The upward movement of the jackshaft applies force to the"spring ba'r 5 iend thus 2 loadsaithe zspecimen through the medium oithe measuringxbar 25," the fvertical rods zz and- 23% the cross bar"20and the upper' gr- 1. The

spring have t =bendsa upwardlyiunder the loading action IOf therjackgand iwhenz'the' -:1oad reaches the 2,000 pound settingptheabair ilope'ra'tes the plunger 50 upwardly to move' the hand iifi away. from thecontact. 59; zthusibreaking Ethe circuit" for:v the ampliiyingztubeUT;whereupon itceasesfiringiandthus deenergizes the up direction relay--Utoaopen itsrcontactstl ti The opening-oi the contacts "U111ideenergizes-the motor 4 I thus stop pingpit The :de's'ired indrementwofthe load is now -on thei i'test -"specimeni and the tes'ter reads thecounting,:.-meter-1| I=2 and enters ithat reading on his chart ofi the-test-;==-

Immediately tthet-tnext. 'in'o'rement; of I load of 2,000 pounds-isapplied to the specimen by-irotatinggthe di'al 56 =furthen in elockwis'edir'ection until its 4,000 pound marking comes-opposite the-zero pointer55. This clockwise rotationuofithe dial 56 from its2,000pound:positiontoits 4;000p0und position:causes-thercontact 59-120engage the con trol handi5'l and carryit along;-; 1 The engagement ofthe icontact. 59 withi-the handt 5T closes the cir-' cuitto -the-'updirectiorriamplifying tube UT; thus energizingeit: as before: describedto'again start the -motor toraise. the *jack sufificientlyito in creasethe "load to. 4,000 pound5; As :this action isscompletedpthe bending'aofthe-spring bar 5 lbyreason: of --the flCICiitiOHZ-itO the :load causesthe plunger 54* to -move the control hahd awayfrom the. contact segment59 andzthus' 'open 'the circuit for the tubeIU -I 'Which in: turnr'deenergizes the up" directiomrelayU and thus stop'ssthemot'oriAgainthetester'reads the countingimetend i2 and en ters thereadingon hischartv A third: increment: 0f: loa'd 01532 000 pounols "is apliedwimmediatelyJoy moving the dialhlockwi'se until-its point ion-6,000issoppositethe zero po'iiit er; It shouldsbe remembered:that'thefirstspring 5 I iSi'n0W in engagement: withi the second -'spring- 5 l a andthe measuring banisenteririg its second range where thehandawiilicorr-esp'orid :to a pres sure :of 2,000 pounds insteads ofe4;000'-pounds'.

:With thisunderstandingiit -will be seenthattne dial need bemovedionlmzhneefourthlthe dis'tance heretofore 'movedainincreasin'grtheload by -2,000 pounds.-

As .the dial is moved-Ito a position:correspond memo- 6,000 pounds,iitcauses r-the contact- 59l to engage; the' liandl 51 and carry it with-'iti The engagementof .thexcontact'and theha-ridlagai n-w energizes-ther motorz ras:previousiyadescribed o raise-the ja'ck and;therebyinerease' :thi'jac-h pres sure to the-.uesireo. eooopauncqoads-es the jack rises, the two spring bars bend upwardly until atthe 6,000 pound point the hand 51 is moved away from the contact 59,thus opening the circuit for the relay UT and thereby stopping the motorat this point. The tester now notes the reading of the counting meter onthe curve sheet.

Immediately, the next and final increment of load of 2,000 pounds isapplied to the specimen by rotating the dial 56 further in clockwisedirection until its 8,000 pound marking is opposite the zero pointer 55.This movement causes the contact 59 to engage the hand 51 and move itfrom its 6,000 pound position to its 8,000 pound position. Theengagement of the contact and the hand starts the motor as beforedescribed and it operates the jack to raise the load on the specimen to8,000 pounds, when the further bending of the spring bar and 5Ia movesthe plunger 54 to separate the contact 59 and hand 51 and thus stop themotor with the loadstanding at 8,000 pounds. The attendant now reads themeter and notes the reading on the curve sheet.

The loading readings are now completed and the machine is prepared formaking the desired creep-rupture test of the specimen at the 8,000pounds constant load. To do this, it will be assumed that pinion 95 ismoved into mesh with the gear wheel 94 and tightened it on its shaft 96to connect the jack gear mechanism with the pen carriage so that thecarriage will move the pen vertically in proportion to the elongation ofthe test specimen; that the switch 130: is closed to start the clock;that the switch KU is closed, thus enabling the motor to run when thehand 51 is engaged by the contact 59 if the load drops; and that thehand 58 is moved counterclockwise until it is in a position whichrepresents a load of approximately 1% greater than the 8,000 pound loadat which the test is to be made.

As timev passes, the clock mechanism 13 moves the pen horizontally onthe curve sheet. It will be assumed now that the specimen elongates asmall amount, thereby permitting the cross bar 20 to move upwardly ashort distance and with it the rods 22 and 23, thus decreasing the bendin the loading bars 5| and5la and permitting is again energized to startthe motor to raise the.

jack until the 8,000 pound load is restored to the specimen, and theconsequent bending of the bending bars 5| and Ma causes the hand 51 tomove away from the contact 59 and thus again open the circuit for thetube UT to stop the motor with the load restored on the specimen.

The elongation of thespecimen necessary to start the motor to restorethe load is very small, but the test instrument and the spring bars 51and 5m are sensitive and will operate to restart the motor approximatelyas soon as the load is decreased a very small amount by a minuteelongation of the specimen so that the load on the specimen will be keptat approximately the predetermined constant value selected for it.

The operation of the gear train in raising the jack to restore the loadon the specimen also moves the pen carriage upwardly a distancecorresponding to the elongation of the test specimen but mechanicallymultiplied many times in proportion thereto. This is efiected bytheoperation of the worm wheel 33,-the worm 34, shaft 40 and gear wheel 49because the gear wheel 49 ro-.

tates the gear wheel 92, the shaft 93. the beveled gears 94 and 96 andthe vertical shafts 82 and 83 to movethe pen carriage upwardly. Hencewhen the jack is raised by the motor in response to an elongation of thespecimen until the load is restored on the specimen, it moves the pencarriage upwardly in accordance with the elongation of the specimen buta distance multiplied many times in proportion thereto by the magnifyinggear ratio.

The apparatus will be left in its present condition and every time thespecimen elongates under the load, the spring bars 5| and 5la will movethe hand 51 counterclockwise to start the motor, as described. As theload is restored, the hand 57 moves clockwise and stops the motor.Meanwhile, the raising of the jack in restoring the load moves the pencarriage. This load-restoring action will be repeated many times duringthe progress of the test.

When the clock was started at the beginning of the test, it rotated itsworm I00 to rotate the worm wheel lill and by it the drive shaft 19.

The operation of the drive shaft 19 moves the pen i l in a horizontaldirection over the curve sheet on the curve board. Inasmuch as the penis moved upwardly in accordance with the strain of the test specimen andhorizontally in accordance with the passage of time, it will draw acurve on the curve sheet giving a creep-time curve.

It will be assumed now that, in restoring the load to the predeterminedconstant value, the motor over-runs in raising the jack. When the jackrises higher than it should in restoring the load, the upward bending ofthe spring bars 5| and 5la moves the control hand clockwise into contactwith the reversing hand 58. The contact of the hands 51 and 58 energizesthe amplifying tube DT by the circuit, L+, I22, DT, 58, 51 to ground.The energized tube DT causes energize.- tion of the down direction relayD to close its contacts DI and open its contacts D2. The closing or" thecontacts DI energizes the reversing relay R by the circuit L+, Hi, I24,I26, KD, DI, R to ground and also energizes the starting relay S by thecircuit L+, l2l, HI, I24, I26, DI, 5, U2 to ground. The energizedreversing relay R opens its contacts R2 and R4 and closes its contactsRI and R3 to cause reverse operation of the motor. The energized relay Scloses its contacts Si and S2 thus energizing the motor and it starts inreverse operation and thereby operates the belt 44 and the gearing 41,49, etc., to lower the jack, thus causing the control hand to movecounterclockwise away from the reversing hand. As the control hand 5'!leaves the reversing hand 58, it opens the circuit through the tube DTand thus stops the motor.

It will be assumed now that the specimen has been under test for a longtime and that it finally ruptures. The rupture of the test specimenopens the auxiliary control circuit through the coil of the relay Hwhich upon being deenergized opens its contacts HI and H2 therebydeenergizing the clock 13 to stop its further action and alsodeenergizing the relay S which opens its contacts SI and S2 thusdeenergizing the motor 4| to prevent its further operation. It should benoted that when the test specimen ruptures, the spring I I5 raises thenut 2] oil the washer H1 and thus completely breaks the auxiliarycontrol circuit even though any slivers on the ruptured test specimenmay be making an electrical contact.

After the test is completed and the test specimen removed, the jack maybe returned to a lower position by closing the push button switchiaami'diovingtne "hand 1 st or the instrument} 52-: into engagemn-twiththe hand 58 to thereby cnerg'iaethe down direction amplifying tube DT-and-thusthe-downdirection switch D to reverse. the-motor 4-! and starthim the down direction. 'Ihc' -mot'ormay be stopped by opening the mainlirie-swltch-MS or the-switch KD. The motor neednch be used-to-returnthejack to ,a lower positionas it may be lowered-by loosening gears92:ah'd- 48 and rotating the gear wheel 49- by hand-until the jack is:in-.the desired 1 position.

By -the foregoing arrangement of theapparatus, it will beseenthat I haveprovided a simple and inexpensive machine forp'roducinga creep curve torupture, Itwillzalso be seen that the machine is simple inconstruction,accurate in ope-ration and one which will require practicallynotattentionfrom the timeit is started until possibly. several days.later when the test is completed. It will also be understood that themeans for. soregulating 'themotor on the .jack that the force. measuringbar is; extended a constant amount notonlykeeps theload-constant throughthettestbut serve s a's a meansfor operating the simple recordingmechanism of this machineand thereby eliminates sources; of-'error inrecording the amount of creep/of the specimen.

Although I have illustrated and described only one specific embodimentof my invention, it is to be understood that changes therein andmodificaticns thereofcmay be-made without departing from the spirit andscope oi-the invention.

I .cla'imas my invention:

1': In a-machinesfortesting a specimen of -material, a frame, a specimendeforming device mounted oni'the frame, means-for attaching one endoithe-specimen-to the frame, a resilient means connecting theother enactthe specimen to the deforming *device, a motor for operating thedefiorming device to loadthe specimen, means responsive to operation ofthe resilient means when the, specimen is, loaded for controlling themotor to maintain the load on the specimen-:at an approximately constantvalue, a :clock mechanism, andmeans responsive to operation'ofthadeforming means. and to operation of the 'clockmechanism. forproducing. a creep-time ciirveforsthespecimen.

2. In a,;machine..for testinga specimen of material, a frame, adeforming device mounted on theirame,'meansforconnecting one end of thespecimen totheirame, means for connecting the other end-of thelspecimentocth'e deforming device, said second mentioned connectingmeansineluding a measuring bar having a first spring section for lowdeforming loads and a second spring-section disposed'to be engaged byandbe defiected-by-thefirst spring.section when the deforming loadexceeds a predetermined value, and a measuring instrument responsive todeflection of the first spring section for giving a two-range reading onthe deforming load on the specimen.

3. In a machine for testing a specimen of material, a frame, a deformingdevice mounted on the frame, a motor for operating the deforming deviceto load the specimen, means for connecting one end of the specimen tothe frame, resilient means for connecting the other end of the specimento the deforming device, means responsive to the action of the resilientmeans when the specimen is loaded for controlling the motor to maintainthe load on the specimen at a predetermined value, and a recording meansresponsive to operation of the deforming device for recording anindication proportional to the movement of the I42 deforming device andtherefore proportionalato the -e1ong ationof the-specimen.

4. In a machinefo-i-' determining the. plastic flow,- or-creep-, ofmaterials, a frame, a. jacl,

mounted on the framameansior connecting one end of a test piece to theframe, aresilientgmean-s for connecting the other end of thetestpieceitothe free end oathe jaclefor a-test, afurn'acedon keeping thetest pieceat a constant temperature amotive-means, means operable by themotive means-for operating thejack to load the test piece, meansresponsive to operationo-f the resi-le.

lent means during-atest for controllingthe motor tomaintain-the loadonthe-test piece at a predeterminedz.value-,.- a. clock mechanism, andmeansres'ponsive to operation of the C10Ck'.meOh-1- anism vand-toope-ration ofthenjack= duringatest for. producing a creep-time curve forthe test piece. 1

5. Inamachine. for testinga specimenof'magv terial, a. frame,a,vfurnace.for maintaining. the specimen atca. constant. temperature, a.loading means comprising a jackmounted on the frame, means for.fastening.-one end :of the specimen to the frame, arresili'ent. meansfor fastening-the other. endoi the specimen to the jack, amotive meansfor operating thejack to load the s'pecie men, acontrol means responsiveto action of :the resilient meansupon elongation of the specimen forcausing the motive.- means to. maintain -th'eload on thespecimen .ataconstant value, aiclock mechanism, -a.=. recording means. responsive-.'to operation of theicloc-k mechanism and :to oper-.- ation ofthe'loadingmeans inmaintainingacom stant load on the. specimen forproducing v-a creep-time. curve, aucontrol circuit connected throughthe. specimen for maintaining the mar chine in testing operation, andmeans responsive to rupture-of the specimen for. moving oneof rupturedpartsaway :from its other part.

6. In a machine-for determining the plasticfiow, or creep, of materials,a frame, a measuring bar having. an elastic segment, means for cornnecting one end :ofatest pieceito @thenframe and its other end :totheends 'ofzthe measuring :bar; a furnace for keepingthe test zpiecetat'a constant temperature, a jack mounted .on the, frameein;

position to engagethe elastic segment, a motor, means for connecting.and disconnecting the mo-. tor with a sour'ceot-energyv forz atestoperation,

a main gear mechanism connected with the-Jack.

and operable by :the motor for operating. theej ack to-1oad the testpiece, a switching instrument mounted on the measuring-banand responsiveto movement of the. elastic :segmentiinrespo'nse to; elongation of thetest piece-for. controllingthe motor to. maintain :a predetermined loadonthe testpiece, a pen for tracing-a curve. onsamurve sheet, anauxiliary gear responsive to operation of the main gear mechanism formoving the pen in one direction in magnified proportion to movement ofthe jack in maintaining the load on the test piece, and a clockmechanism for moving the pen in another direction during the test,whereby the pen is caused to trace a creep-time curve for the testpiece.

7. In a machine for determining the plastic flow, or creep, ofmaterials, a frame, a jack mounted on the frame, means for connectingone end of a test piece to the frame, a resilient means for connectingthe other end of the test piece to the jack, a furnace for maintainingthe test piece at a constant temperature, a motor, means for connectingthe motor to a source of electrical energy when starting a test and fordisconnecih ing'it at the end of a test, a main gear mechanism connectedwith the jack and operable by the motor for operating the jack to loadthe test piece, a switching instrument responsive to-ac-. tion of theresilient means during a test for controlling the motor to maintain theload on the test piece at a predetermined value during test, a. clockmechanism, and a recording means responsive to operation of the clockmechanism and to operation of the jack in maintaining the load on thetest piece for tracing a creep-time curve for the test piece.

8. In a machine for determining the plastic flow, or creep, ofmaterials, a frame, a measuring bar having an elastic segment, means forconnecting one end of a test piece to the frame and its other end to themeasuring bar, a furnace for keeping the test piece at a constanttemperature, a jack mounted on the frame in position to :engage theelastic segment, a motor, meansfor connecting and disconnecting themotor to a source of energy for a test operation, a gear mechanismconnected with the motor for operating the jack to load the test piece,a switching instrument responsive to movement of the elastic segment forcontrolling the motor to maintain the load on the test piece at apredetermined value, a pen for tracing a curve on a curve sheet, anauxiliary gear means responsive to operation of the main gear mechanismin raising the jack for moving the pen in one direction in magnifiedproportion to the elongation of the test piece, a clock mechanism formoving the pen in another direction during the test, whereby the pen is.caused to trace a creep-time curve for the test ;piece, and a recordingdevice responsive to oper- =ation of the auxiliary gear for recordingthe disetance the jack rises to provide data for use in :making aloading curve and for extending the .curve when the pen is moved beyondthe curve :sheet before a test is completed.

, 9. In a machine for determining the plastic :fiow, or creep, ofmaterials, a frame, a measuring ibar maving a first spring .bar and asecond spring bar disposed to be engaged by the first spring bar at apredetermined load, means for connecting one end of a test piece to themain frame and its other end to the measuring bar, a furnace for keepingthe test piece at a constant temperature, a jack mounted on the mainframe in position to engage the first spring bar, a motor, a controlsystem for connecting the motor to a source of energy for a test of thetest piece, a main gear mechanism connected with the jack and operableby the motor for operating the jack to load the test piece, a switchinginstrument mounted on the measuring bar and responsive to movement ofthe first spring bar in response to 16' elongation of the test piece forcontrolling the motor to maintain a predetermined load on the testpiece, a holding device for a curve sheet, a pen, for tracing a curve onthe curve sheet, an auxiliary gear responsive to operation of the maingear mechanism for moving the pen in one direction in magnifiedproportion to the movement of the jack in loading the test piece, aclock mechanism for moving the pen in another direction during the test,whereby the pen is caused to trace a creep-time curve for the testpiece, a recording device responsive to operation of the auxiliary gearfor recording the distance the jack moves in maintaining the loading onthe test piece to provide data for use in a loading curve and forextending the curve when the pen is moved beyond the curved sheet beforethe test is completed, and means responsive to rupture of the test piecefor stopping the clock mechanism and the motor.

10. A measuring device for a testing machine comprising a bar having twoparallel longitudinal slots through its central portion to form an innerspring and an outer spring with a boss disposed on the central portionof one of the springs adjacent to the other spring a predetermineddistance therefrom and a measuring instrument mounted on the bar withits plunger movably disposed through the central portion of the bar andthe inner spring into contact with the outer spring, whereby an initialforce applied to the outer spring will operate the plunger to give onerange of measurement and an increased force sufficient to move the outerspring into contact with the inner spring will operate the plunger togive a second range of measurement.

MICHAEL J. MANJOINE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,154.280 Nadai et a1 Apr. 11,1939 2,185,971 Achtel et a1. Jan. 2, 1940 2,353,999 Counts July 18, 1944269,941 Johannsen Jan. 2, 1883 2,014,357 Klemperer Sept. 10, 19352,075,968 Von Hydekampf Apr. 18, 1944 2,351,572 Kingston June 13, 19442,346,981 Manjoine et al. Apr. 18, 1944 2,243,413 Buckingham May 27,1941 2,350,722 Buckingham June 6, 1944 FOREIGN PATENTS Number CountryDate 6,476 Great Britain 1903

